What function the humidifier include? - 4L (1.06Gal) water tank lasts about 13 hours on the maximum flow setting. - 360° rotatable mist nozzle to adjust mist direction freely. - 7-colour LED night-light (Purple, Indigo, Blue, Green, Yellow, Orange, Red) with solid and cycling color settings. Can be switched on to create a beautiful luminous environment. - Automatic shut-off when water level is very low. - LED display; Indoor temperature show, Built-in timer; - Whisper-quiet (<35dB) operation using new Ultrasonic Technology. - Integrated aroma diffuser slot with sponge. Just put a few drops of your favorite essential oil on the sponge and enjoy great aroma diffusion while humidifying the air. - Includes water filter. The filter should be replaced after about 500 hours of use. Additional filters can be purchased from 1byone.